Close-coupled articulating headrest

ABSTRACT

An articulating headrest for treatment chairs such as dental chairs, to adapt such chairs for use in procedures with the dentist seated. An adapter bracket mounts the headrest to the existing structure of the chair and slideably receives a tongue member which bears the balance of the headrest. A link is pivotally attached both to the upper end of the tongue and to a cushion support plate carrying a cushion for the patient&#39;&#39;s head, and both pivot points are clamped by a single clamp mechanism. The combined motions of sliding the tongue in the bracket and pivoting the cushion support plate and the link about the pivot points allow selection of a wide variety of headrest positions for upper jaw work, pediatric dentistry, X-ray, and procedures with the dentist seated and the patient reclining.

United States Patent Rasmussen CLOSE-COUPLED ARTICULATING HEADREST [451 May 27, 1975 Primary ExaminerCasmir A. Nunberg Attorney, Agent, or Firm-Schapp and Hatch [57] ABSTRACT An articulating headrest for treatment chairs such as dental chairs, to adapt such chairs for use in procedures with the dentist seated. An adapter bracket mounts the headrest to the existing structure of the chair and slideably receivesa tongue member which bears the balance of the headrest. A link is pivotally attached both to the upper end of the tongue and to a cushion support plate carrying a cushion for the patients head, and both pivot points are clamped by a single clamp mechanism. The combined motions of sliding the tongue in the bracket and pivoting the cushion support plate and the link about the pivot points allow selection of a wide variety of headrest positions for upper jaw work, pediatric dentistry, X-ray, and procedures with the dentist seated and the patient reclining.

12 Claims, 7 Drawing Figures CLOSE-COUPLED ARTICULATING HEADREST BACKGROUND OF THE INVENTION The present invention relates to a CLOSE- COUPLED ARTICULATING I-IEADREST, and more particularly to headrests for a dental chair or similar treatment chair yielding a thin-profile configuration for operative techniques in which the patients head is disposed adjacent the dentists lap.

Conventional dental chairs such as the older chairs manufactured by the Ritter, Weber, and S.S. White companies are generally constructed with a unitary back cushion and either a single curved pad or a bifurcated two-pad headrest, with both the back cushion and the headrest mounted on a common back support member. A linkage allows adjustment of the headrest position in some models, but in all models, the depth of the headrest and linkage in the direction generally perpendicular to the plane of the back cushion makes it difficult for the dentist to operate while seated alongside a fully reclining patient. r

Among the desirable qualities of a satisfactory headrest for dental chairs of this type are adaptability to a wide range of procedures and adjustability to all sizes of patients, both adults and children. Prior art headrests have suffered from a lack of flexiblity in both respects, and, indeed, separate devices were often required to adapt the chair for children.

SUMMARY OF THE INVENTION The close-coupled articulating headrest of the present' invention replaces the conventional headrest apparatus on a treatment chair such as a dental chair, to adapt it to a wider range of uses, including dentistry with the patient fully reclining with his head above the dentists lap. The headrest or split back of this application provides a thin profile of the back of the dental chair to allow such sit-down dental operations and also permits full articulation of the headrest position without sacrifice of the thin profile.

The close coupling possible with the headrest allows the patient to be positioned with head thrown back for upper jaw work, or with the head raised from the plane of the back of the chair, as is necessary for certain X-ray procedures. It also allows the head cushion to be swung down flat against the front of the back cushion to shorten the chair for children, all without projecting too far to the rear of the chair to interfere with use with the patient fully reclined and the dentist seated.

As discussed at greater length in my co-pending applications, Ser. Nos. 383,452 and 384,013, filed July 27, 1973 and July 30, 1973, respectively, both entitled SPLIT BACK DENTAL CHAIR APPARATUS, the headrest may be provided either as part of the original equipment of a new treatment chair, or as a kit for conversion of older chairs. For the latter purpose, the bracket which receives the longitudinal tongue of the headrest is made adaptable to several configurations of backs and back support members of conventional chairs, as shown in those applications so that the installation may be made with minimal modification of the existing chair.

Accordingly, it is a principal object of the present invention to provide an articulating headrest for dental chairs and the like which yields a thin longitudinal profile of the chair to permit dental operations with the patient's head above the dentists lap.

It is a further principal object of the present invention to provide an articulating headrest of the character described which provides a wide range of positions without sacrifice of the thin profile.

Yet another principal object of the present invention is to provide an articulating headrest of the character described which may be adapted to a wide range of existing models of dental chairs without extensive alterations.

Still another object of the present invention is to provide an articulating headrest of the character described which effectively shortens the chair for pediatric dentistry.

A still further object of the present invention is to provide an articulating headrest of the character described which may be adjusted to elevate the patients head above the plane of the back of the chair for certain procedures.

It is another object of the present invention to provide an articulating headrest of the character described which is adaptable for upper jaw work on a reclining patient.

Further objects and advantages of the present invention will become apparent as the specification proceeds, and the new and useful features thereof will be fully defined in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred form of the present invention is illustrated in the accompanying drawings, forming part of this specification, in which:

FIG. 1 is a perspective view of the close-coupled articulating headrest of the present invention, shown attached to a portion of the back of a dental chair, with dashed lines and circular arrows indicating the axes of pivotal motion of the headrest and the motion about those axes;

FIG. 2 is a side elevational view of a typical prior art dental chair apparatus, with the lower portions thereof shown broken away;

FIG. 3 is a series of side elevational views, on a reduced scale, of the headrest of the present invention attached to the back of a dental chair, with the lower portions of the chair shown broken away, illustrating four different positions of adjustment of the headrest;

FIG. 4 is a rear elevational view, on an enlarged scale, of the headrest of the present invention, with the lower portion thereof broken away;

FIG. 5 is a crosssectional view taken approximately along the plane of lines 55 of FIG. 4;

FIG. 6 is an exploded perspective view on a reduced scale of the headrest of the present invention, corresponding to the upper portion of FIGS. 4 and 5; and

FIG. 7 is a fragmentary cross-sectional view on an enlarged scale, taken approximately along the plane of lines 77 of FIG. 1.

While only the preferred form of the present invention has been shown here, it should be understood that various changes and modifications may be made, within the scope of the claims attached hereto, without departing from the spirit of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in detail, there is shown in FIG. 1 the back 11 of a dental or treatment chair having a close-coupled articulating headrest system generally indicated at 12. The headrest system 12 includes a tongue member 13 adapted for longitudinally adjustable engagement with the back 11 of i the chair, a link member 14 pivotally attached at one end to the tongue member 13, and a cushion support plate 16 pivotally attached to the opposite end of the link member 14. The cushion support plate 16 is attached to the link member 14 at a point adjacent one edge of the plate 16, and a clamp means generally indicated at 17 is provided for releasable clamping of the pivotal motion of the link member 14 both with respect to the tongue member 13 and with respect to the plate 16.

The pivotal end of thetongue member 13 bears a yoke bracket 18, with a short rod 19 serving as an axle passing through both arms of the yoke. The lower end of the link member 14 is formed into a split bearing 21, journalled about the rod 19. The rod 19 has flattened areas at each end (see FIG. 6) for engagement by a pair of screws 22 in the arms of the yoke bracket 18, so that it is held both against rotation and longitudinal motion. The lower, or distal, end of the tongue member 13 is engaged in a keyway or slot 23, shown here as forming a part of the back support member 24 of the chair. The tongue member 13 slides longitudinally in the keyway 23, and is secured at the desired longitudinal position by a retaining means, shown here as a knob 26 threaded through the lower end of the tongue member 13.

The knob 26 when tightened bears against the right hand side of the keyway, as shown in FIG. 7, to clamp the tongue member 13 against the opposite face of the keyway 23. A slot 27 in that opposite face of the keyway 23 allows a range of longitudinal motion for the knob 26. Although a knob 26 serves as the retaining means in the present embodiments, other means such as the ratchet and pawl mechanisms shown in my above-cited applications may likewise be used. Also, with chairs in which the back support member 24 is not itself suitable for receiving the tongue member 13, the tongue member 13 may be received by an adapter which is in turn received either by the back support member 24 or secured directly to the back 11 of the chair, as is also shown in my above-cited applications.

At the end of the link member 14 opposite the first split bearing 21 is a second split bearing 28, which journals a second short rod 29, similar to the short rod 19. As with the rod 19, the rod 29 has flattened ends, which are held by screws 31 against the shoulder areas 32 formed in the cushion-receiving side of the cushion support plate 16. The rod 29 thus forms a fixed axle for the pivotal motion of the link member 14 and the plate 16 with respect to each other.

The two split bearins 21 and 28 are both clamped by a single unitary clamp means 17, which includes a tension rod 33 passing through both of the jaws formed by the slot 34 in the split bearing 21. The tension rod 33 also passes transversely at an angle through the jaws formed by the slot 36 in the upper split bearing 28. The body of the link member 14 has a longitudinal trough 37 cut into its rearward side and running most of the length of the link 14, including both jaws of the upper split bearing 28, and the tension rod 33 passes longitudinally through the trough 37.

The uppermost jaw of the split bearing 28 is formed into a yoke 38 by the passage of the trough 37 through it. A pin 39 passes through the arms of the yoke 38 and journals a handle 41 by passing in turn through the arms of a yoke 42 formed by slotting the upper end of the handle 41. The arms of the yoke 42 project upward and forward beyond the pin 39, as shown in FIG. 5, a short distance to receive a pin 43. The pin 43 passes through the upper end of the tension rod 33, so that counterclockwise movement of the handle 41 draws the tension rod 33 upward. The tension in the tension rod 33 draws head 44 on the lower end of the rod 33 upward against the lower jaw of the split bearing 21 to draw that jaw upward to clamp motion about the axle 19. At the same time rod 33 transmits tension through the pin 39 to the upper jaw of the split bearing 28 to clamp motion about the axle 29.

The clamp 17 remains taut due to the toggle-type movement provided by the pins 39 and 43 and the arms of the yoke 42. The pin 43 need not, however, pass over-center with respect to the pin 39, as the friction in the parts is sufficient to offset the small transverse forces produced by the tension in the rod 33 when the pin 43 is near the over-center point.

The cushion support plate 16 is of somewhat rounded trapezoidal shape as shown in elevation in FIG. 4, and is slightly concave in form as shown in the crosssectional view of FIG 5. As may be seen from FIG. 5, the axis of pivotal motion of the plate 16 with respect to the link 14, ie the axis of the rod 29, lies generally within the plane of the plate 16. This configuration is produced both by the forward curve (to the right in FIG. 5) of the upper end of the link member 14 and the releif formed in the back of the plate 16 by a trough 46 lying between the reinforcing ribs 47 and by the relatively deeply vertically cut relieved area or slot 48. The point of attachment of the plate 16 to the link 14, via the axle 29, is located adjacent the top edge of the plate 16 to make possible the wide range of positional adjustments, some of which are shown in FIGS. 3A, 3B, 3C, and 3D. Together with the location of the axis of movement of the plate with respect to the link adjacent to or within the plane of the plate itself, the location of that axis near one edge of the plate makes possible certain positionings of the headrest which are clearly out of the question with the prior art headrests, such as that shown in FIG. 2. For one example, the close coupling of the link upper end and the head supporting surface in the present invention allows the positioning shown in FIG. 3D for shorter adult and juvenile patients, while the remoteness of connection between the link and the head supporting surface make that configuration impossible in the prior art device shown in FIG. 2. In that prior art device, the length of the arm 53 places a substantial distance between the head supporting surface 51 and the upper axle 54.

As may be seen from FIG. 5, the headrest of the present invention also has the lower axis of motion, that between the link 14 and the tongue 13 about the axle 19, so positioned that it may be brought into a closely adjacent relation to the cushion support plate 16 when that position is desired. Part of this positioning is made possible by the forward curve of the lower end of the link 14 and part by the forward curve of the upper end of the bracket 18 (i.e., to the right as viewed in FIG. 5). It can be appreciated by inspection of FIG. 2 that it is not possible to bring the head supporting surface 51 of the prior art headrest into juxtaposition with or even near the lower axle 56, and the typical curve of the bracket 57 is precisely the opposite of that of the present invention.

As may be seen from FIG. 3A through D, the ability to bring the axes of motion into close juxtaposition with the head supporting surface is important both in producing the flexibility of positions of adjustment of the present headrest, and in yielding the thin profile, particularly as shown in FIGS; 3A and 3B, and also to an extent in' FIG. 3D. This thin profile permits the dentist to operate on a reclining patientwhile seated with the patients head immediately above the dentists lap. Due

to the lack of close-coupling in the'prior art'me'chanism shown in FIG. 2., the mechanism will protrude a considerable distance below the back of the chair when the chair is used in a reclining position, and thus prevent the dentist from operating comfortably on the patient while seated alongside. The structure of the present invention protrudes a minimum depth behind the back of the chair while elevating the patients head to approximately the level of the front of the back cushion 11 of the chair. The positioning of the attachment of the plate 16 to the link 14 adjacent one edge of the plate 16, the positioning of the axis to lie in or adjacent to the plane occupied generally by the plate 16, and the forward positioning of the lower axis formed by the rod 19 all contribute to the production of a very thin profile, while retaining the maximum flexibility of positioning.

A head cushion 49 is attached to the cushion support plate 16 by an appropriate technique. Preferably, and as here shown, the attachment is made by adhering a strip 61 of fabric material, of the type commercially available as Velcro, to the front surface of the plate 16. If the material covering the cushion 49 is a twisted loop material such as is often found in upholstery, it will serve itself as a mating surface for engagement with the Velcro hook material 61; if not, a mating strip ofVelcro loop material may be adhered or sewn to the rear side of the cushion 49.

In the illustration in FIG. 2 of the typical prior art headrest, the handle for clamping motion of the headrest about the pivot points is indicated at 58. Another handle 59 releases the bracket 57 from engagement with the keyway or slot in the back support member 24 to permit longitudinal movement or the headrest or its removal.

From the foregoing it may be seen that a closecoupled articulating headrest has been provided which can adapt many present models of dental and other treatment chairs to a wide range of headrest positions while retaining the thin profile which permits sitdown dentistry. Among the range of positions available are those effective for upper jaw work, short patients, X-ray procedures and orthodontic and prosthetic work, with the patient in fully reclined or sitting up modes, at the option of the dentist, or without requiring modifications of the chair structure to accommodate these modes.

I claim:

1. A close-coupled articulating headrest system for treatment chairs and the like, comprising a tongue member adapted for longitudinally adjustable engagement with the back of the chair,

a link member pivotally attached at one end thereof to said tongue member,

a dished cushion support plate pivotally attached adjacent the upper edge thereof to the end of said link member opposite said tongue member, and

overcenter toggle clamp means adapted for simultaneous releasable locking of pivotal motion of said link member both withire'spect to said tongue member and-with respect'to said'c'uShion support plate.

'2. A close-coupledarticulatingheadrest system as described in claim 1 and wherein said link member is attached to said tOnguemember adjacent the pivotal end of said tongue member, the distal portion of said tongue member being engageable with the back of the chair and having a retaining means thereon for locking said longitudinal "adjustment. j

3. A close-coupled articulating headrest system as described in claim 1 and wherein said clamp 'means comprises a unitary mechanism having a clamp han'dle operative to clamp both pivotal motions by a single motion of the clamp handle to a clamping position lying flat against said link member, said clamp means being formed so that said clamp handle projects angularly away from said link member when said clamp means is released.

4. A close-coupled articulating headrest system as described in claim 3 and wherein said clamp means includes split bearings as the pivotal attachment of said link member to said tongue member and the pivotal attachment between said tongue member and said cushion support plate, a tension rod connected between said split bearings simultaneously, said tension rod being operatively connected to said clamp handle for clamping and unclamping movement thereby.

5. A close-coupled articulating headrest system as described in claim 4 and wherein said split bearings are formed integrally in the opposite ends of said link member, and said split bearings are journaled on pins secured against rotation in said tongue member and said cushion support plate.

6. A close-coupled articulating headrest system as described in claim 1 and wherein the axis of pivotal motion of said cushion support plate with respect to said link member is located adjacent the plane in which said cushion support plate generally lies.

7. A close-coupled articulating headrest system as described in claim 6 and wherein the end of said link member attached to said cushion support plate is curved forward toward said cushion support plate and said cushion support plate has relieved areas thereon cooperative with said link member, whereby the axis of pivotal motion between said link member and said cushion support plate is brought into close juxtaposition with the plane generally occupied by said cushion support plate.

8. A close-coupled articulating headrest system as described in claim 1 and wherein the axis of pivotal motion of said link member with respect to said tongue member is adjustably disposable adjacent said cushion support plate.

9. A close-coupled articulating headrest system as described in claim 8 and wherein the end of said link member attached to said tongue member is curved forward in the direction to bring it toward the cushion support plate when that plate is disposed adjacent the axis of pivotal motion between said link member and said tongue member.

10. A close-coupled articulating headrest system as described in claim 8 and wherein the pivotal end of said tongue member is attached to a bracket which is in turn pivotally connected to said link member, said bracket being curved forward in the direction to bring it toward the cushion support plate when that plate is disposed adjacent the axis of pivotal motion between said link member and said tongue member.

11. A close-coupled articulating headrest system as described in claim 8 and wherein the axis of pivotal motion of said cushion support plate with respect to said link member is located adjacent the plane in which said cushion support plate generally lies.

12. A close-coupled articulating headrest system as described in claim 11 and wherein the end of said link member attached to said cushion support plate is curved forward toward said cushion support plate and said cushion support plate has relieved areas thereon cooperative with said link member to bring the axis of pivotal motion therebetween into close juxtaposition with the plane generally occupied by said cushion support plate, and the pivotal end of said tongue member is attached to a bracket which is in turn pivotally connected to said link member, said bracket, and the end of said link member attached to said bracket both being curved forward in the direction to bring them toward the cushion support plate when that plate is disposed adjacent the axis of pivotal motion between said link member and said tongue member, said headrest system further comprises a flattened head cushion attachable to said cushion support plate. 

1. A close-coupled articulating headrest system for treatment chairs and the like, comprising a tongue member adapted for longitudinally adjustable engagement with the back of the chair, a link member pivotally attached at one end thereof to said tongue member, a dished cushion support plate pivotally attached adjacent the upper edge thereof to the end of said link member opposite said tongue member, and overcenter toggle clamp means adapted for simultaneous releasable locking of pivotal motion of said link member both with respect to said tongue member and with respect to said cushion support plate.
 2. A close-coupled articulating headrest system as described in claim 1 and wherein said link member is attached to said tongue member adjacent the pivotal end of said tongue member, the distal portion of said tongue member being engageable with the back of the chair and having a retaining means thereon for locking said longitudinal adjustment.
 3. A close-coupled articulating headrest system as described in claim 1 and wherein said clamp means comprises a unitary mechanism having a clamp handle operative to clamp both pivotal motions by a single motion of the clamp handle to a clamping position lying flat against said link member, said clamp means being formed so that said clamp handle projects angularly away from said link member when said clamp means is released.
 4. A close-coupled articulating headrest system as described in claim 3 and wherein said clamp means includes split bearings as the pivotal attachment of said link member to said tongue member and the pivotal attachment between said tongue member and said cushion support plate, a tension rod connected between said split bearings simultaneously, said tension rod being operatively connected to said clamp handle for clamping and unclamping movement thereby.
 5. A close-coupled articulating headrest system as described in claim 4 and wherein said split bearings are formed integrally in the opposite ends of said link member, and said split bearings are journaled on pins secured against rotation in said tongue member and said cushion support plate.
 6. A close-coupled articulating headrest system as described in claim 1 and wherein the axis of pivotal motion of said cushion support plate with respect to said link member is located adjacent the plane in which said cushion support plate generally lies.
 7. A close-coupled articulating headrest system as described in claim 6 and wherein the end of said link member attached to said cushion support plate is curved forward toward said cushion support plate and said cushion support plate has relieved areas thereon cooperative with said link member, whereby the axis of pivotal motion between said link member and said cushion support plate is brought into close juxtaposition with the plane generally occupied by said cushion support plate.
 8. A close-coupled articulating headrest system as described in claim 1 and wherein the axis of pivotal motion of said link member with respect to said tongue member is adjustably disposable adjacent said cushion support plate.
 9. A close-coupled articulating headrest system as described in claim 8 and wherein the end of said link member attached to said tongue member is curved forward in the direction to bring it toward the cushion support plate when that plate is disposed adjacent the axis of pivotal motion between said link member and said tongue member.
 10. A close-coupled articulating headrest system as described in claim 8 and wherein the pivotal end of said tongue member is attached to a bracket which is in turn pivotally connected to said link member, said bracket being curved forward in the direction to bring it toward the cushion support plate when that plate is disposed adjacent the axis of pivotal motion between said link member and said tongue member.
 11. A close-coupled articulating headrest system as described in claim 8 and wherein the axis of pivotal motion of said cushion support plate with respect to said link member is located adjacent the plane in which said cushion support plate generally lies.
 12. A close-coupled articulating headrest system as described in claim 11 and wherein the end of said link member attached to said cushion support plate is curved forward toward said cushion support plate and said cushion support plate has relieved areas thereon cooperative with said link member to bring the axis of pivotal motion therebetween into close juxtaposition with the plane generally occupied by said cushion support plate, and the pivotal end of said tongue member is attached to a bracket which is in turn pivotally connected to said link member, said bracket and the end of said link member attached to said bracket both being curved forward in the direction to bring them toward the cushion support plate when that plate is disposed adjacent the axis of pivotal motion between said link member and said tongue member, said headrest system further comprises a flattened head cushion attachable to said cushion support plate. 